Bundling strap

ABSTRACT

An improved self-locking bundling strap comprising, in one form, a plurality of pairs of spaced, generally transverse narrow slits of predetermined length extending from the edges of the strap inwardly towards the center of the width of the strap, each pair being separated by a selectively proportioned center portion, to facilitate the severance of an excess portion thereof by rotatably twisting said portion while substantially preserving the initial strap strength and flexibility. Other embodiments include obliquely angled slits having either a straight or curvilinear contour.

United States Patent 1 91 Kohke 6/1965 Schwester et al. 24/16 PB [5BUNDLING STRAP 3,186,047

[75] Inventor: Stephen Kohke, Bridgewater FOREIGN PATENTS ORAPPLICATIONS Township, 1,278,571 10/1961 France 24/16 PB [73] Assignee:Thomas & Betts Corporation, 1,435,102 3/1966 France 24/16 PB Elizabeth,NJ. 1 Primary Examiner--Donald A. Griffin Filed; p 1971 Attorney-DavidTeschner and Jesse Woldman 21 Appl. No.: 181,347 I 57 ABSTRACT 1 US Clmm24/16 PB An improved self-locking bundling strap comprising, in [51]Int. Cl 63/00 one form, a plurality of pairs of spaced, generally trans-[58] Field R 17 B verse narrow slits of predetermined length extending24/17 A 17 206 A PB 73 from the edges of the strap inwardly towards thecenter P 74 of the width of the strap, each pair being separated by aselectively proportioned center portion, to facilitate [56] ReierencesCited the severance of an excessportion thereof by rotatably 1 I g 1twisting said portion while "substantially preserving the UNITED STATESPATENTS initial strap strength and flexibility. Other embodiments 3; rfit lt include obliquely angled slits having either a straight or s a er2,361,506 10 1944 Smith 24/16 PB ux curl/meat contour 3,022,557 2/1962Logan 24/16 PB UX 9 Claims, 12 Drawing Figures E 1 0 I l I 1 a2 June 19,1973 BUNDLING STRAP BACKGROUND OF THE INVENTION P. Schwester et al., andentitled Self-Clinching Bundling Strap assigned to the assignee of theinstant invention, are generally constructed in such manner that afterthe strap has been wrapped about the articles to be bundled the excessof the strap body portion not required for such bundling may be severedtherefrom. In

general practice such severing is accomplished by means of installationtools which not only attach and tighten the strap to the articles to bebundled, but also cause severing of the excess portion of the body.Comparatively, any type of cutting devices such as side cutter's,shears, scissors or the like may also be employed to remove the excess.It is obvious from the prior art method of employment of the straps thata tool is essential for removal of the excess portion and sufficientspace is required to permit the tool to be employed. The absence of thetool or the inability to employ the same results in a strap which has anexcess portion of its body extending beyond the loop portion, which isboth unattractive and which may interfere with the use of the bundledarticles. Prior art methods for accomplishing the severance of theexcess portion which included, for example, selectively scoring ornotching the body portion of the strap, have generallyprovedunsatisfactory because of the severe reduction in flexibility andstrength resulting therefrom.

SUMMARY OF THE INVENTION The present invention overcomes thedifficulties and limitations noted above with respect to prior artdevices by providing a steplessly variable, selectively severablebundling strap advantageously arranged to avoid the necessity for theuse of cutting or severing tools to accomplish the severance of adesired portion thereof from the remaining strap body. One or more pairsof generally transverse narrow slits, arranged either in opposing oroffset relation, are introduced into the body portion of the strap andextend from the sides towards the center of the width thereof apredetermined distance to provide a generally centrally disposed uncutportion selectively proportioned to maintain adequate strength andflexibility in the body portion for the use contemplated, whilepermitting the portions of the strap body adjacent thereto to beconveniently severed by axially rotating one portion in relation to theother, as by twisting or the like. The slits extend between, andcommunicate with, both the upper and lower body portion surfaces alongeither equal or unequal lengths the'reat, the latter arrangementfacilitating increased coplanar bending flexibility in a preferreddirection. Additionally, the slits may be obliquely angled with respectto the longitudinal axis of the body portion, and formed either straightor curved, the. latter configuration being extremely useful where it isdesired to maintain the severed central portion within the confines ofthe outer ends of the strap. It is therefore an object of this inventionto provide an improved bundling strap.

It is another object of this invention to provide means for effectingthe directionally selective severability of a portion of a bundlingstrap.

It is a further object of this invention to eliminate the need for toolsin severing the excess portion of a bundling strap.

It is still another object of this invention to provide a means forsevering the excess portion of a bundling strap from the remainderthereof by twisting.

It is still a further object of this invention to provide an improvedbundling strap arrangedto maintain the bending flexibility thereofwhile: rendering a portion thereof particularly amenable to severance bytwisting.

It is yet a further object of this invention to provide pointed out inthe following description and claims and illustrated in the accompanyingdrawings, which disclose, by way of example, the principles of theinvention and the best modes which have been contemplated for carryingthem out.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of abundling strap constructed in accordance with the concepts of theinvention.

FIG. 2 is a side elevational view of the bundlingstrap of FIG. I wrappedabout a plurality of articles.

FIG. 3 is a fragmentary. side elevational view of a portion of thebundling strap of FIG. I wrapped about an article in a manner differentthan that shown in FIG. 2.

FIG. 4 is a front perspective view of the bundling strap of FIG. 1showing the manner in which the excess body portion may be removedtherefrom by twisting.

FIG. 5 is a fragmentary top plan view of a portion of the body portionof the bundling strap of FIG/1 showing the effect of transverse bendingthereon.

FIG. 6 is a fragmentary side elevational view of a por' tion of the bodyportion of the bundling strap of FIG. 1 showing the effect of coplanarbending. thereon.

FIG. 7 is a front transverse sectional view of a portion of the bodyportion of the bundling strap of FIG. 1

taken along the lines 7--7 of FIG. 1.

FIG. 8 is a front transverse sectional view of a portion of a bundlingstrap constructed in accordance with another embodiment of theinvention.

FIG. 9 is a fragmentary perspective view of a portion of the bodyportionof the bundling strap of FIG. 1 showing the manner in which a portionmay be removed therefrom by twisting.

FIGS. 10, Hand 12 are fragmentary perspective views of a portion of thebody portion of a bundling strap constructed in accordance with furtherembodiments of the invention.

Similar elements are given similar reference characters in each of therespective drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIGS. 1 and 2,there is shown a bundling strap 20 constructed in accordance with theconcepts of the invention, and comprising a head portion 22 having atransverse aperture 24 therethrough, and

engaging means in the form of a pawl 26 extending at least partiallyinto aperture 24. Extending from the head portion 22 is a generally flatelongated body portion 28 terminating in a preferably tapered tailportion 30. Extending inwardly from the opposing sides 32, 34 of thebody portion 28 towards the center of its width, and extending betweenand communicating with both the upper and lower surfaces 36, 38respectively, of body portion 28, are a plurality of generallytransverse narrow slits 40 disposed along the length of the body portion28 in generally spaced relationship. Although shown in FIG. 1 asarranged in generally opposed aligned relationship, slits 40 may bepositionally altered to provide an essentially'staggered arrangement asat 42 in FIG. 12, and may be aligned in generally oblique angularrelationship with the longitudinal axis of body portion 28, as at 44 inFIG. 10, without departing from the spirit of the invention.Additionally, slits 40 may be selectively formed in generallycurvilinear fashion as shown at 46 in FIG. 11, the various advantages ofsuch modifications being more particularly described below. Althoughslits 40, 42, 44 and 46 may be formed during the manufacture of thestrap 20, as by molding or the like, it has been found that thesubsequent formation of such slits by the use of a razor-like slittingtool applied to the formed strap generally results in the addedadvantage of substantially reducing the twisting force re quired toeffect the desired severance without adversely affecting the flexibilityor tensile strength of the strap. Extending longitudinally along thebody portion 28 of bundling strap intermediate the opposing slits is anuncut central portion 48, more clearly shown in FIG. 7. Thecross-sectional area of portion 48 is selectively proportioned to insureadequate strap strength and flexibility while enabling one portion ofthe body portion 28 to be conveniently removed from the remaining lengththereof merely by applying a rotational twist thereto, directionally asshown at 52 in FIG.

9, thus avoiding the need for special tools to effect, for 7 example,the desired removal of the excess portion of said body portion'28extending beyond the head portion 22 after the bundling strap 20 hasbeen wrapped about one or more articles (FIG. 2), and the tail portion30 inserted into the head portion aperture 24 and drawn therethrough,and locked by means of pawl 26, as shown for example, in FIG. 4.Depending upon the type of material from which the bundling strap 20 isformed, and the strength and flexibility desired, the ratio of thecross-sectional area of the central portion 48 to the transversecross-sectional area of the body portion 28 may vary from about 50percent to about 95 percent thereof. Examples of plastic materialssuitable for use within the aforementioned range may include,.

but are not limited to, nylon, delrin, polypropylene, polyethylene, andpolyvinyl chloride, and other nonmelt formable materials. Where desired,the slits 40 may be disposedin the body portion 28 in such manner as toform a central portion 54 (FIG. 8) having a crosssection generallydefining an isosceles trapezoid, substantially as shown. Sucharrangement may be particularly advantageous where, for example, it iseither necessary or desirable to provide increased coplanar flexi bilityin a preferred direction. The particular configuration illustrated inFIG. 8 will, for example, permit the body portion of a bundling strapsuch as 20, modified accordingly, to be more readily coplanarly flexeddownwardly as directionally indicated by the arrow 56 in FIG. 6, whileoffering greater resistance to flexing in a direction opposite thereto,in supplement to the inherent flexibility of the bundling strap 20absent the inclusion of such slits therein. Although the terminatingedges 49, 51 (FIG. 7) and 53, (FIG. 8) of the central portions 48 and54, respectively, are shown as substantially linear, it will be readilyapparent to those skilled in the art that such edges may becurvilinearly contoured or otherwise varied without departing from thespirit of the invention. The resistance of the body portion 28 tolateral deflection when subjected to a force applied directionally asindicated by arrows 58, 60 in FIG. 5 is not appreciably decreased as aresult of the presence, of slits 40 therein. because of the close,substantially abutting relationship of the walls defining slits 40. Forexample, where aforce such as that indicated by the arrows S8, 60 inFIG. 5 is applied to the body portion 28, the side of the body portion28 to the right in FIG. 5 is urged into compression, while the opposite,or left, side is subjected to a tensile force. As shown, the slits 40 tothe left in FIG. 5 are caused to widen slightly while those on the rightside are caused to close, thereby resisting further deflection withinthe inherent compressive strength of the material employed. As a resultof the aforementioned properties, the necessity for substantiallyincreasing the size of bundling strap required in a particularapplication beyond that generally employed in unslit prior art straps isadvanta I geously avoided, while such structure provides a convenientmeans for effecting the severance of a selective portion thereof withoutthe need for tools or other cutting devices. The further advantages ofthe disclosed arrangement may be more fully appreciated by reference nowto FIG. 3. As shown therein, bundling strap 20 may be wrapped about anarticle such as in such manner as to cause a relatively severe coplanardeflection of the body portion 28 at the point of entry of said portion28 into the strap head portion 22, as at 82. In the event strap 20 weretransversely scored or notched, as is provided in many commonly employedprior art bundling straps, such deflection would tend to cause aweakening or parting of the strap at the point of deflection, therebyresulting in a loss of retention and engagement. However, because of themaintenance of the integrity of the central body portion of the instantdevice, and the corresponding retention of coplanar flexibility andtensile strength resulting from the unique arrangement of the slittedstructure disclosed herein, such problems are essentially avoided.

As may be more clearly seen in FIGS. 7 and 8, each of the centralportions 48 and 54 are so proportioned as to provide a substantiallyuninterrupted area for engagement with the bundling strap pawl 26, thuspermitting essentially infinitely variable stepless engagement betweenthe pawl 26 and body portion 28 independent of the position of slits 40.

As indicated heretofore, slits 40 may be modified as at.44 and 46 inFIGS. 10 and 11, respectively, within edges 72, 74 formed by thecommunication of the planar slit surfaees 64 with the respective bodyportion sides 76, 78 (FIG. It will be readily apparent to those skilledin the art that other slit configurations and arrangements employinga-combination of slits 40, 42, 44 and 46, or' suitable variationsthereof, may be readily utilized without departing from the spirit ofthe invention.

The longitudinalspacing between slits 40, 42, 44 or 46 may beselectively arranged to provide either a uniform, nonuniform,continuous, or discontinuous pattern, depending upon the incrementalvariation desired and/or use contemplated. Longitudinal slit spacing inthe range of from about one thirty-second to about three-eighths incheshas been found to be generally adequate for most purposes where it isdesired to limit the extent of protrusion of the remaining strap bodyportion 28 beyond the strap head 22 after severance. It will be readilyapparent, however, that such rangeis not intended to be limiting, butmay be suitably varied as desired. For example, slits 40, 42, 44 or 46may be longitudinally disposed in relatively close adjacent relationshipalong a first predetermined length of body portion 28, and more widelyspaced along a secondpredetermined length thereof. It will also bereadily apparent to those skilled in the art that slits 40, 42, 44 or 46may be so proportioned as to provide differing crosssectional dimensionsalong the length of body portion 28, where, for example, it is necessaryor desirable to selectively vary the flexibility thereof. 7

The embodiments of the invention in which the exclusive property orprivileges are claimed are defined as follows: 1 v i 1. In a bundlingstrap of'the type having a head end portion having a transverse aperturetherethrough, a tail end portion, an elongated body portion therebetweenhaving afirst surface, a second surface, a first side and a second side,and proportioned to be received within said head end portion transverseaperture, and engaging means in said head end, portion for steplesscoacting engagement with at least one of said first and second surfacesof said body portion, the. improvement comprising: said 'body portionhaving at least one pair of slits for enhancing the severance of aselective length of said body portion from the remainder thereof, eachslit of a pair thereof extending inwardly, respectively, from anopposite one of said body portion first and second sides a predetermineddistance towards the center of the width of said body portion providinga central portion thereat, each of said slits further extending betweenand communicating with said body portion first and second surfaces, eachof said slits being generally curvilinear and forming generally arcuatesegments adjacent said first and said second sides of said body portionand extending longitudinally slightly beyond said body portion centralportion thereby providing a partial shield about said central portionupon the severance of said body portion intermediate said pair of slits.

2.ln a bundling strap of the type having a head end portion having atransverseaperture therethrough, a tail end portion, an elongated bodyportion therebetween having a first surface, a second surface, a firstside and a second side, and proportioned to be received within said headend portion transverse aperture, and engaging means in said head endportion for stepless coacting engagement with at least one of said firstand second surfaces of said body portion, the improvement comprising:said body portion having at least one pair of slits for enhancing theseverance of a selective length of said body portion from the remainderthereat, each slit of a pair thereof extending inwardly, respectively,

from an opposite one of said body portion first and sec-.

ond sides a predetermined distance towards the center of the width ofsaid body portion, each of said slits further extending between andcommunicating with said body portion first and second surfaces, each ofsaid slits communicating with said body portion first surface along afirst predetermined length,and communicating with said bodyportionsecond surface along a second predeterminedlength different thansaid first predetermined length, wherein the area of said body portionin termediate said pair of opposingly disposed slits has a cross-sectiongenerally defining an isosceles trapezoid providing a greater surfacearea and resistance to coplanar deflection at the one of said bodyportion first and second surfaces adjoining the longer of the parallelsides defining said isosceles trapezoidal area.

3. The improvement as definedl in claim 2, wherein said firstpredetermined length is shorter than said second predetermined length.

4. The improvement as defined in claim 2, wherein said firstpredetermined length is longer than said second predetermined length.

5. The improvement as defined in claim 2 wherein said isoscelestrapezoidal area comprises a maximum of about percent of thecross-sectional area of said body portion as measured generallytransverse to the longitudinal axis thereof. i

6. The improvement as defined in claim 2 wherein said isoscelestrapezoidal area comprises at least about 50 percent of thecross-sectional area of said body portion as measured generallytransverse to the longitudinal axis thereof.

7. The improvement as defined in claim 2 wherein said isoscelestrapezodial area is in the range of about 50 percent to about 95 percentof the cross-sectional area of said body portion as measured generallytransinches to about three eighths inches.

1. In a bundling strap of the type having a head end portion having atransverse aperture therethrough, a tail end portion, an elongated bodyportion therebetween having a first surface, a second surface, a firstside and a second side, and proportioned to be received within said headend portion transverse aperture, and engaging means in said head endportion for stepless coacting engagement with at least one of said firstand second surfaces of said body portion, the improvement comprising:said body portion having at least one pair of slits for enhancing theseverance of a selective length of said body portion from the remainderthereof, each slit of a pair thereof extending inwardly, respectively,from an opposite one of said body portion first and second sides apredetermined distance towards the center of the width of said bodyportion providing a central portion thereat, each of said slits furtherextending between and communicating with said body portion first andsecond surfaces, each of said slits being generally curvilinear andforming generally arcuate segments adjacent said first and said secondsides of said body portion and extending longitudinally slightly beyondsaid body portion central portion thereby providing a partial shieldabout said central portion upon the severance of said body portionintermediate said pair of slits.
 2. In a bundling strap of the typehaving a head end portion having a transverse aperture therethrough, atail end portion, an elongated body portion therebetween having a firstsurface, a second surface, a first side and a second side, andproportioned to be received within said head end portion transverseaperture, and engaging means in said head end portion for steplesscoacting engagement with at least one of said first and second surfacesof said body portion, the improvement comprising: said body portionhaving at least one pair of slits for enhancing the severance of aselective length of said body portion from the remainder thereat, eachslit of a pair thereof extending inwardly, respectively, from anopposite one of said body portion first and second sides a predetermineddistance towards the center of the width of said body portion, each ofsaid slits further extending between and communicating with said bodyportion first and second surfaces, each of said slits communicating withsaid body portion first surface along a first predetermined length, andcommunicating with said body portion second surface along a secondpredetermined length different than said first predetermined length,wherein the area of said body portion intermediate said pair ofopposingly disposed slits has a cross-section generally defining anisosceles trapezoid providing a greater surface area and resistance tocoplanar deflection at the one of said body porTion first and secondsurfaces adjoining the longer of the parallel sides defining saidisosceles trapezoidal area.
 3. The improvement as defined in claim 2,wherein said first predetermined length is shorter than said secondpredetermined length.
 4. The improvement as defined in claim 2, whereinsaid first predetermined length is longer than said second predeterminedlength.
 5. The improvement as defined in claim 2 wherein said isoscelestrapezoidal area comprises a maximum of about 95 percent of thecross-sectional area of said body portion as measured generallytransverse to the longitudinal axis thereof.
 6. The improvement asdefined in claim 2 wherein said isosceles trapezoidal area comprises atleast about 50 percent of the cross-sectional area of said body portionas measured generally transverse to the longitudinal axis thereof. 7.The improvement as defined in claim 2 wherein said isosceles trapezodialarea is in the range of about 50 percent to about 95 percent of thecross-sectional area of said body portion as measured generallytransverse to the longitudinal axis thereof.
 8. The improvement asdefined in claim 2, wherein said body portion comprises a plurality ofsaid pairs of slits longitudinally disposed along the length of saidbody portion.
 9. The improvement as defined in claim 8, wherein saidslits are generally longitudinally spaced one from another in the rangeof from about one thirty-second inches to about three-eighths inches.